Do I lag all my pipes?

[Triassic]

I'm about to start 1st fix plumbing and wondered if I should be lagging all the pipes, both hot and cold?

 

I also recall someone posting about using pre-lagged 15mm barrier pipe, has anyone used it and is it more cost effective? Who is the supplier?

 

Manifolds - Which one is the best and most competitively priced?

[scottishjohn]

If all are inside the hot envelope of house --then probably not worth the extra expense 

outside that then yes

 

[Moonshine]

My common sense would be to only lag pipes (hot and cold) in unheated spaces. 

[Triassic]

Is condensation on cold pipes likely to be an issue?

Edited February 5, 2019 by Triassic

[ADLIan]

Details are in Appr Doc L1A and Building Services Compliance Guide - primary circulation pipes for HW services should be insulated even if inside insulated envelope

[scottishjohn]

6 minutes ago, Triassic said:

Is condensation on cold pipes likely to be an issue?

would depend on flow through them ,as they will heat up if not flowing all the time

[le-cerveau]

I specced all pipes to be lagged (overkill).  I have long DHW runs with a circulation system so lagging to keep down losses, and there's nothing worse than warm cold water!

[scottishjohn]

7 minutes ago, ADLIan said:

Details are in Appr Doc L1A and Building Services Compliance Guide - primary circulation pipes for HW services should be insulated even if inside insulated envelope

theres your answer then --hot only is requirement 

[scottishjohn]

Just now, le-cerveau said:

I specced all pipes to be lagged (overkill).  I have long DHW runs with a circulation system so lagging to keep down losses, and there's nothing worse than warm cold water!

I suppose if you are a "sunamp man " then you will not have long runs cos you will have a sunamp in each bathroom and not main hot storage

[Triassic]

21 minutes ago, ADLIan said:

Details are in Appr Doc L1A and Building Services Compliance Guide - primary circulation pipes for HW services should be insulated even if inside insulated envelope

So the next question is, where can I get rolls of 10 and 15mm pipe insulation at a reasonable price?

[Jeremy Harris]

I'd also suggest that lagging cold pipes inside the heated envelope is wise.  I didn't bother to lag the cold water pipes in our services room (which is inside the house) and had problems with condensation dripping from them in the summer.  They are all now insulated with armaflex.  Armaflex isn't cheap, but I've found that it's both easier to use and more effective than the rigid plastic foam stuff.

[Triassic]

2 hours ago, JSHarris said:

They are all now insulated with armaflex.  Armaflex isn't cheap, but I've found that it's both easier to use and more effective than the rigid plastic foam stuff.

I've noticed that Armaflex comes in different wall thicknesses. Which one would be appropriate for use inside a highly insulated house?

[Jeremy Harris]

7 minutes ago, Triassic said:

I've noticed that Armaflex comes in different wall thicknesses. Which one would be appropriate for use inside a highly insulated house?

 

 

I used a mix of two wall thicknesses, really as much to do with the practicality of installing it as anything else.  I tried to use the thicker, 19mm wall stuff as much as possible, but there were some tight places where I could only fit the thinner 13mm wall stuff.  If I've read the regs correctly, then I think that it's only the 19mm wall thickness stuff that complies. 

[gravelld]

Lag them; don't try to do two jobs (DHW and space heating) with one solution. Also, if you build to a high spec you've got a potential over heating problem.

[Ed Davies]

Does lagging DHW pipes really make much difference, if you're not circulating water? It depends on the pattern of use, of course, but even unlagged pipes take quite a while to cool down so if more water is used quickly it'll still be warm. But often it's many hours between uses so even with lagging the pipe will be cold on the next use so it's only a relatively narrow period of time where it'll make much difference.

 

E.g., I only normally do one lot of washing up a day, in the evening, so lagging on the pipe to the kitchen sink will make absolutely no difference (other than maybe raising the temperature of the delivered water by 1°C or so).

 

[Cpd]

6 hours ago, Triassic said:

Is condensation on cold pipes likely to be an issue?

My cold pipe that runs in my kitchen was terrible for dripping condensation, it was like a self made dehumidifier ! Once lagged it was all sorted. 

[le-cerveau]

15 hours ago, scottishjohn said:

I suppose if you are a "sunamp man " then you will not have long runs cos you will have a sunamp in each bathroom and not main hot storage

No, I am a SunAMp man with central storage, 4 units, SunAmp is not designed as a point of use system but as a replacement for cylinders.

[Onoff]

14 hours ago, JSHarris said:

 

 

I used a mix of two wall thicknesses, really as much to do with the practicality of installing it as anything else.  I tried to use the thicker, 19mm wall stuff as much as possible, but there were some tight places where I could only fit the thinner 13mm wall stuff.  If I've read the regs correctly, then I think that it's only the 19mm wall thickness stuff that complies. 

 

Same here, thicker where possible, thin wall if that's all that'll fit.

 

I've unfortunately got CH pipes, though lagged, running outside the albeit poor thermal envelope.

 

"Byelaw 49" rings a bell.

[scottishjohn]

2 hours ago, le-cerveau said:

No, I am a SunAMp man with central storage, 4 units, SunAmp is not designed as a point of use system but as a replacement for cylinders.

I thought it was just a heat store ?

how you deploy it is your choice ,so why not  at point of use

would save heat losses between bathrooms if long pipe runs  in a big house  or granny flat annex

just a suggestion 

[le-cerveau]

9 minutes ago, scottishjohn said:

how you deploy it is your choice ,so why not  at point of use

Mine are configured as low temp and high temp, effectively a Thermal Store without the losses.  Even if you just used a PCM54 unit it is equivalent to over 100L of water do I really put a DHW tank in each bathroom (5), downstairs WC, laundry and kitchen.  I would then have to run primary pipes to each unit to heat them (mine are not electric).  I would also size each one for each room, so two capable of filling a bath and/or shower, three more shower only.  A central point allows for diversity, I can assume not all outlets in use at once, distributed need full capacity at each outlet.  They are also not cheap.

 

If you have electric ones, how do you decide which get the solar divert first?

[Stones]

18 hours ago, Triassic said:

Is condensation on cold pipes likely to be an issue?

 

Yes, a certainty (or certainly what I have seen) within heated envelope.  

 

22 minutes ago, scottishjohn said:

I thought it was just a heat store ?

how you deploy it is your choice ,so why not  at point of use

would save heat losses between bathrooms if long pipe runs  in a big house  or granny flat annex

just a suggestion 

 

Using an individual Sunamp unit for each room starts to become a pretty expensive way of doing it.  I know because I looked at having two separate Sunamp locations servicing different areas.  

 

 

[Onoff]

12 hours ago, Cpd said:

My cold pipe that runs in my kitchen was terrible for dripping condensation, it was like a self made dehumidifier ! Once lagged it was all sorted. 

 

I noted that in the height of Summer my copper, mains cold in, within the the loft would run with condensation.

 

Would it be worth harvesting that "free" water?

[scottishjohn]

1 minute ago, le-cerveau said:

Mine are configured as low temp and high temp, effectively a Thermal Store without the losses.  Even if you just used a PCM54 unit it is equivalent to over 100L of water do I really put a DHW tank in each bathroom (5), downstairs WC, laundry and kitchen.  I would then have to run primary pipes to each unit to heat them (mine are not electric).  I would also size each one for each room, so two capable of filling a bath and/or shower, three more shower only.  A central point allows for diversity, I can assume not all outlets in use at once, distributed need full capacity at each outlet.  They are also not cheap.

 

If you have electric ones, how do you decide which get the solar divert first?

think that would be a question for JS for the control of the units,

I was assuming most would be using PV for rechariging nothot water 

but if using smaller units then it might work out better with current software on the c uni Q have where it won,t charge till well depleted ,so it might be self diverting --

definately one for JS or NICK

he will have a  way for sure .

but of course your design of house will have a bearing on what is best for you 

comes back to old story of not making anything till design is set in stone  to be right first time

thats the hard bit .LOL

 I doubt i will  think of all scenarios  when designing 

this is why I,m still thinking of having  0.75 - 1m service cavity "wet wall" down one side of house connected to service room ,so it easy to make any changes in spec in the future  without ripping things apart. maybe won,t be possible --time will tell 

[scottishjohn]

14 minutes ago, Stones said:

 

Yes, a certainty (or certainly what I have seen) within heated envelope.  

 

 

Using an individual Sunamp unit for each room starts to become a pretty expensive way of doing it.  I know because I looked at having two separate Sunamp locations servicing different areas.  

 

 

whilst i can see the  advantages of sunamp  in some circumstances --excess pv etc 

I personally and i,m not wanting an argument

am not convinced of the overall advantage  considering costs  at this stage 

maybe that will change   as the technology improves 

which is exactly why i want service void to  be able simply alter things in the future 

[scottishjohn]

I can see far more better immediate  uses in the motor industry for it .

make smaller units in hundreds of thousands and price will drop 

instant heating of car in the morning ,with very little energy usage ,only a circulation pump ,

water heating for your motorhome for living space and DHW  as you drive along 

wi-fi from house before you open it up --etc.

it is using excess free heat to charge it up anyway ,will come from engine exhaust or cooling system  or maybe from regenerative  braking system  or drive motor on an electric car 

or maybe a solar thermal system on house to charge it up --rather than using a  big thermal store for DHW or UFH

but price needs  to drop  first I think